Heat exchangers are devices used to transfer heat from one medium to another. Heat exchangers come in many forms, and can have different structures depending on the heat load to be transferred and the environment in which the heat exchanger is used. Vehicles such as automobiles and aircraft utilize heat exchangers to transfer heat generated by the vehicle to a heat transfer medium, such as air or coolant fluid flowing around or through the heat exchanger. For example, air may flow over a coil carrying hot engine coolant, and heat from the coil may be released into the air. In addition, large amounts of heat can be generated by an aircraft engine or other aircraft components, especially in large aircraft, and it may be necessary to quickly and efficiently transfer the heat away from the aircraft. For instance, a Next Generation Jammer (NGJ) pod attached to the side of a fighter aircraft may need to release a heat load of 40 to 60 kW at any given time.
Heat exchangers in aircraft are generally internally mounted in a duct or a plenum of the aircraft, and the duct or plenum may draw air into the aircraft through inlet ducts. However, the design and configuration of internally mounted heat exchangers may be constrained by the size of the aircraft in which they are carried. That is, some aircraft may not have sufficient packaging volume on board to accommodate an internally mounted heat exchanger. In other cases, the heat exchanger may need to be very small in size due to packaging size limitations imposed by the size of the aircraft. Consequently, many heat exchanger designs and configurations have been driven by a desire to maximize heat exchange capacity while minimizing the size of the heat exchanger. Additionally, internally mounted heat exchangers may have insufficient surface area to completely release, or dump, the heat load generated by an aircraft or aircraft component.
In order to address this problem, strip heat exchangers have been designed for use on the side of aircraft pods (e.g., an ALQ 99 or ALQ 184 jammer pod). Strip heat exchangers can be used in situations where there are significantly lower heat loads and higher allowable coolant temperatures. However, such designs may have inadequate heat exchanging capacity in situations where there are higher heat loads and lower required coolant temperatures, because there may be insufficient surface area on the strip heat exchanger for dumping the required heat load.
Accordingly, there is a need for a heat exchanger design and configuration that provides improved heat transfer capability for larger heat loads and is configured to operate in a vehicle having packaging size limitations, such as an aircraft.